It is known that a quasi-monochromatic X-ray resulting from Compton scattering is obtained by collision of an electron beam with a laser beam (for example, Non-Patent Document 1).
In “small-sized X-ray generating device” of Non-Patent Document 1, as shown in FIG. 1, an electron beam 82 accelerated by a small-sized accelerator 81 (X-band acceleration tube) is allowed to collide with pulse laser beam 83 to generate an X-ray 84. The multi-bunch electron beam 82 generated by an RF electron gun 85 (thermal RF gun) is accelerated by the X-band acceleration tube 81, and collides with the pulse laser beam 83. The hard X-ray 84 having a time width of 10 ns is generated by Compton scattering.
This device is miniaturized by using an X-band (11.424 GHz) corresponding to a frequency four times as high as that of an S-band (2.856 GHz) for general use in a linear accelerator as an RF. For example, it is predicted that the hard X-ray having an X-ray intensity (number of photons) of about 1×109 photons/s and a pulse width of about 10 ps is generated.
Further, means for measuring a profile of an electron beam or a laser beam is disclosed in Non-Patent Documents 2 and 3.
The profile measuring means disclosed in Non-Patent Document 2 is three chambers arranged at a collision point of an electron beam with a laser beam. The chambers are formed integrally with a beam pipe to maintain a vacuum of a beam line and to allow various diagnosis devices to be inserted in the beam line by remote control. Further, the profile measuring means measure positions and sizes of the electron beam and the laser beam. Each of the three chambers has a screen incorporated therein. In the central chamber, a combined scanner in which a wire scanner and a knife-edge scanner are formed integrally with each other is incorporated. By combining angle adjustment and parallel displacement of the laser beam, the positions of the electron beam and the laser beam are adjusted so as to be accurately matched with each other on the screens of the three chambers.
The profile measuring means disclosed in Non-Patent Document 3 is mounted with a fluorescent screen, a wire scanner, and an optical transition radiation (OTR) target.
[Non-Patent Document 1] K. Dobashi et al., “Development of Small-Sized Hard X-Ray Source Using X-Band linac”, The 27th Linear Accelerator Meeting in Japan, 2002
[Non-Patent Document 2] T. Omori, M. Fukuda, “Generation and Polarization Measurement of High-Quality, Short-Pulse Polarized Photon Beam”, Nippon Butsuri Gakkaishi, Vol. 58, No. 4, 2003
[Non-Patent Document 2] F. Sakamoto, et al., Japanese Journal of Applied Physics, Vol. 44, No. 3, 2005